9309317 Engel This research concerns the development and verification of a method which will reduce the cycle time when manufacturing thick composites using resin transfer molding. The resin transfer molding (RTM) process is a low pressure, low temperature method of transferring a thermoset resin into a mold which contains a fiber preform. While it has been used predominately for manufacturing thin laminates, RTM is ideally suited for manufacturing thick composites, as a mold can easily accommodate three dimensional preforms. However, manufacturing thick section composites is more involved than that of thin sections because of the difficulty with precise process control and the increased time required to infiltrate the fiber preform and cure the resin. A numerical model will be developed to describe the nonisothermal infiltration of thermoset resins into thick fiber preforms. The resin flow will be simulated at the micro scale level by considering the flow or resin around and through heated fiber bundles. Direct heating will temporarily reduce viscosities for increased infiltration rates. Furthermore, the resulting elevated temperature through the mold will reduce curing cycles. This research will be verified experimentally with resin transfer molding equipment and various combinations of conduction heating and resistance heating of the fiber preform, mold and resin. Such a model can be used to decrease the cycle time, such a intra resin transfer molding process. This should reduce cost, while maintaining high quality.
